This research study is examining a drug called Recombinant Keratinocyte Growth Factor (rHuKGF) which may help with the symptoms of dry mouth and mouth sores that you are likely to experience when you receive your cancer treatments. The main purpose of this Phase I/II research study is to find out how safe different doses of Recombinant Keratinocyte Growth Factor (rHuKGF) are. A secondary purpose is to find out whether the study drug rHuKGF will safely help reduce mouth sores and dry mouth in adults like you who have head and neck cancer and are being treated with chemotherapy and radiation therapy.